OFFSET
1,3
COMMENTS
The sequence is started with a(1) = 0 and always extended with the smallest integer not yet present and not leading to a contradiction.
EXAMPLE
The first 12 terms are:
0,1,2,10,20,102,30,3,1020,300,31,40
Their successive digits are:
0,1,2,1,0,2,0,1,0,2,3,0,3,1,0,2,0,3,0,0,3,1,4,0
The nonprime rank digits are here (between parentheses):
(0),1,2,(1),0,(2),0,(1),(0),(2),3,(0),3,(1),(0),(2),0,(3),0,(0),(3),(1),4,(0),
Erasing the digits not in the parentheses:
(0),.,.,(1),.,(2),.,(1),(0),(2),.,(0),.,(1),(0),(2),.,(3),.,(0),(3),(1),.,(0),
The surviving digits are:
0,1,2,1,0,2,0,1,0,2,3,0,3,1,0,...
Those are indeed the digits of the starting sequence.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eric Angelini and Jean-Marc Falcoz, Mar 23 2017
STATUS
approved